Tire pressure, Slime & CO2: Observations

[cmonkey]

Got my seg in Dec 04, put slime in the tires after about a week.
Played with the tire pressure for about a month till I found the sweet spot for my weight and my comfort (about 18psi). Last fill was around Feb/Mar, and last pressure check was last week at the 4th of July parade in Anaheim. In just over 4 months time I had only lost couple pounds of pressure! I'm a firm believer in slime!

Last night I had to go around an obstacle and would up getting some brambles stuck in both my tires. I got on the seg today and found my tire pressure down to about 10PSI. I ran a hose over the tires and couldn't find the leak, slime to the rescue again.

I've gotten my hands on one of those CO2 pumps, and I have some thoughts.... If I fill up my tires with CO2, and since CO2 molecules are about 140% bigger than oxygen atoms.... that should result in slower air loss, right?

All meanderings aside.... just a tip on those CO2 inflators... Always inflate carefully and with the business end of the inflator facing UPWARDS.

While at the parade, I volunteered my inflator to top off a low tire, and not having used one before, I had the business end pointing down. The net result was that in the brief moment that I squeezed the trigger, most the liquid CO2 shot into the tire and in that 1/4 second the pressure went from 8psi to 60psi.

Happy gliding!

I love my magic carpet!

[Dragan]

The only thing I would be concerned about with the slime is what it may be doing to the inside of your tire. I know that it's not recommended for car tires for extended use, but I wonder what kind of interaction it has with the silica/rubber formula in the Seg tire?

It wouldn't appear to have caused yours any trouble so far, though, so maybe it's the way to go.

Those CO2 inflators are real efficient, all right; maybe too efficient. We tried using a small electric compressor in the store and found we spent as much time bleeding off extra pressure as we did filling the tire up in the first place with a hand pump. We eventually abandoned it in favor of a foot pump, overall less hassle, more effective at getting an accurate inflation the first time without risking over filling. After a short while, you'll get a sense of how many times you need to step on the pump to add a pound or 2, or 5. Then it's just count the compessions and you're usually pretty close to the pressure you want
Wayne

Segway of Alberta - Calgary
www.mysegway.ca

[SegwayUtah]

Hmm. I swear by slime -- I put it in i-series HT tires and a year later they're still holding pressure beautifully.

I think that Slime is only good for like 2 or 3 years, but I figure if I ride enough I will replace my tires then anyway :) And if not, I could always rinse out the tires, maybe.

Chris

[Socrates]

Slime looses its function after 6 months more or less. It becomes hard when it dries out.
In my local mountain bike club the riders who have tubeless tires don't use slime but liquid latex from sex shops, it is cheaper, lasts longer and works fine. Because it is of thicker consistence than slime it fills holes from big thorns and the tire does not loose any air. This is no joke, but I have never tried it.

Alexander

[SegwayUtah]

Hmm. I've had Slime in my i-series tires for over a year, and they're still doing great. My tire pressure stays very consistent, and thorns and things don't pose a problem--it's a huge relief.

Now for those Segway tweels . . .

Chris

[Zorba9]

In my off-roading with ETT's I got a 1/4 gash from some rocks - slime kept the tire aired for a day or 2, all the while slowly leaking out and making a mess wherever it was parked if the cut was on the bottom. Then installed a tire plug and solved the problem.

Socrates - liquid latex from a sex shop?? Must be a European thing! :)

KOG

Zorba9.....

[macgeek]

I have been all over 42nd street in New york city haunting sex shops, looking for liquid latex, I have bought many MANY other items for my "seg'x life' but so far the only slime I have encountered were my fellow shoppers.

I'm going to start looking online at porn sites, maybe I can get a better grip on the situation.

Jonathan

"Think outside the car"

[cmonkey]

The only problem with slime i've found so far, is when you don't use your wheels for an exented period of time. I hadn't been on my mountain bike in about 6 months, when I took it out last week and got going about 25-30mph down a hill, and I could feel the slime in my tires. It pooled in hardened in the tube and now I have a really unbalanced wheel. inner tubes are cheap, so no big deal for me.

I did however, see a neat new slime product for (tubless?) tires. It's a slime band, that's about an inch wide and looks like a giant green rubber band. It fits on the inside of your tire. Since it's not a liquid, it won't pool and cause balance issues. (which is probably why it's not recommended for automotive use)

I may have to try that latex trick though.

Dave

I love my magic carpet!

[Tarkus]

Is it only me or does it bother others that for 5 grand they can't keep air in the tires ?

I love my Seg, but there are a few warts.

[Tanasit]

Can the tire be filled with CO2 permanently? I thought it is for temporaly fix since CO2 is extremely sensitive to the temperature changes, thus the pressure may vary excessively. I used to put the pink slime in one of my slow leaking car tire and it threw off the balance. Rebalancing was inpossible because the off balance spot kept shifting. Moreover the pink slime will clog the valve and I later couldn't refill any more !! However, I used the product with self inflation and sealer in a spray can from Pep Boys with my electric scooter tire and it works great.

[cmonkey]

I lost more air, and found out my valve had backed out a bit and my tire was completly flat. I tightened it up and put in an entire 16 gram canister of CO2, and so far no problems. I forget my thermodynamic equations, but for the volume of air and temperature fluctuations that southern california sees... the pressure changes are insignificant. (at least they feel that way when I ride)

I love my magic carpet!

[BarnyFife]

There is a tire dealer chain in my area that uses nitrogen to inflate the tires you buy there. They say it runs cooler and stays in longer also due to its larger molecule.

[KSagal]

I use ETTs from LLC and have no problems. I own a CO2 inflator that I keep with me for emergencies, and inflate the tires from my compressor at home.

Most of the slime I encounter is with the people I meet. I have none in my segway or car tires. I have used the "pep boys" type arosol cans for tempory car repairs, but that is it...

I don't do many curb hops, but do occationally, but find that I don't have to top off my tires on the seg any more often than on my car, which is not too often.

I have often wondered if it was the silicone based tires that sponsor this unhappyness, because the ETTs are a more standard tire rubber and don't seem a problem for me...

Karl Ian Sagal

Each road you travel should be just a bit better for having had you pass.

[Stan671]

I asked the question at the Segway engineer Q&A panel at SegwayFest NH about why the tires loose pressure over time.

The answer talked about leakage of air through the tire and the wheels and the bead between them. Air actually penetrates through the rubber of the tires and the plastic of the wheels. There was a compromise they had to strike between the force of the bead seal and the deformation of the plastic wheels at the bead.

They tried many combinations of tire compound, wheel plastic and bead pressures in order to find the best overall combination.

Since the ETT's are made of a different (softer and more sticky) rubber formula, they may have a lower amount of air seeping through the rubber. This may also help with leakage at the bead. Of course, the plastic wheels are the same.

Stan Dobrowski